$fname=$_POST['fname'];
$lname = $_POST['lname'];
$Phone = $_POST['Phone'];
$date = date("Y/m/d");
mysql_query ( "INSERT INTO example (fname,lname,Phone,date) VALUES ('$fname' ,'$lname', '$Phone', '$date')")
or die(mysql_error());
当我在代码中编写重复条目时，将显示这些错误：我的主键是电话。
Duplicate entry '' for key 'PRIMARY'
但我想在添加数据之前通过 JavaScript 检查和显示以防止此错误。怎么可能？请完全帮助和电线源。谢谢
$fname=$_POST['fname'];
$lname = $_POST['lname'];
$Phone = $_POST['Phone'];
$date = date("Y/m/d");
$query = "SELECT * FROM example WHERE Phone = '".mysql_real_escape_string($_POST['Phone'])."'";
if (mysql_num_rows(mysql_query($query)) > 0)
{
print "inuse";
}
else
{
mysql_query ( "INSERT INTO example (fname,lname,Phone,date) VALUES ('$fname' ,'$lname', '$Phone', '$date')")
or die(mysql_error());
}